Compression Ratio NissanTohatsu 99

"I'm looking at a couple o

"I'm looking at a couple of used Nissan/Tohatsu's.

One is a Nissan 1998 9.8, the other is Tohatsu 2000 9.9.

What compression ratio should these engines have?

Cheers"

The only thing that is importa

The only thing that is important is that the measured compression is even between the cylinders.

"John, I don't know the ex

"John, I don't know the exact compression numbers. What your looking for is numbers that are close together from cylinder to cylinder. I think a compression reading with numbers deviating less that ten pounds is good. But it is possible to get even compression readings below 90lbs compression. Below 90lbs is pretty much worn out by my standards. This would mean the cylinder walls and rings are shot. Try looking for an online manual and see if these compression readings are listed in the spec section of the manual. I'm pretty sure Tohatsu.com has online manuals that you can download.


Mark."

"My 9.9 Tohatsu engine from 20

"My 9.9 Tohatsu engine from 2002 has always had 11 bar at both cylinders. I meassured it when the engine was new to get a number as a reference. I don't know what it will be in PSI, but most testers has both values."